Among disposable diapers, which are one type of wearing article, there are known to be expandable-type disposable diapers that have fastening tapes and pull-on disposable diapers that are pre-formed into an underpants shape. Both of these types of diapers have a waist opening through which the torso of the wearer is inserted during wearing and leg openings through which the legs of the wearer are inserted. These openings are usually formed by connecting the edge sections of the diaper into a loop. These edge sections are usually configured including a sheet such as a nonwoven fabric. Also, both of these types of diapers have a back-side section arranged on the back side of the wearer during wearing and a stomach-side section arranged on the stomach side. The back-side section and stomach-side section of the diapers are normally configured including a sheet such as a nonwoven fabric.
There are cases where the peripheral edge sections of the waist opening and the leg opening, or the back-side section and the stomach-side section, of a disposable diaper separate from the body of the diaper wearer and become loose or slide down due to the wearer's movement or the like. In order to prevent such an inconvenience, the openings' peripheral edge sections, for example, the peripheral edge section of the waist opening (the waist edge section) in the back-side section and the stomach-side section, are provided with elastic stretchability. Another known technique for a disposable diaper provided with an absorbent body including an absorbent core and a sheet-shaped exterior body joined to the skin-non-contacting side of the absorbent body is to provide the exterior body constituting the back-side section and the stomach-side section with elastic stretchability for the purpose of improving the fit of the diaper to the wearer. In general, in the case of providing a disposable diaper with elastic stretchability, a method is generally used in which string-shaped or band-shaped elastic members in their stretched state are fixed between two substantially non-stretchable sheets via an adhesive, and gathers are formed by allowing the elastic members to shrink.
Also, as a material used in the wearing article, Patent Literature 1, for example, discloses a conjugate stretchable material in which two sheets and an elastic member are intermittently joined in the stretching direction of the elastic member, joints between one of the sheets and the elastic member are provided between joints between the other sheet and the elastic member in the stretching direction, and in each of the sheets, raised protrusion sections are formed between the joints. The conjugate stretchable material disclosed in Patent Literature 1 has many creases that extend in the direction intersecting with the stretching direction of the elastic member, resulting in the formation of a fiber structure having coarseness and fineness at the surface, thus realizing a soft and favorable feel against one's skin. Patent Literature 2 discloses a method of obtaining a nonwoven fabric having superior flexibility by subjecting a thermoplastic polymer nonwoven fabric to gear drawing under a predetermined draw ratio condition.
Patent Literature 3 discloses a method of manufacturing a disposable diaper including a drawing step in which a band-shaped sheet whose stretchability can be increased by drawing is fed between a pair of toothed rollers having teeth and grooves meshed with each other and is drawn in the width direction, thus increasing the widthwise stretchability of the band-shaped sheet. Also, Patent Literature 4 discloses a method of manufacturing a disposable diaper including a step in which a zero-strain stretch laminate web is supplied between pressure applicators having three-dimensional surfaces that are meshed with each other, and elasticity is provided by drawing part of the web through the application of pressure by the applicators. In the methods for manufacturing a disposable diaper disclosed in Patent Literature 3 and 4, an elastic member that forms various types of gathers is fixed between two pre-drawn sheets via an adhesive; that is, the sheets are subjected to draw processing before the elastic member is fixed to the sheets.